EP0193403A1 - "Vogelschwing"-Fehlererfassung für Glasbehälter - Google Patents

"Vogelschwing"-Fehlererfassung für Glasbehälter Download PDF

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Publication number
EP0193403A1
EP0193403A1 EP86301410A EP86301410A EP0193403A1 EP 0193403 A1 EP0193403 A1 EP 0193403A1 EP 86301410 A EP86301410 A EP 86301410A EP 86301410 A EP86301410 A EP 86301410A EP 0193403 A1 EP0193403 A1 EP 0193403A1
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EP
European Patent Office
Prior art keywords
article
light
container
sidewall
base
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP86301410A
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English (en)
French (fr)
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EP0193403B1 (de
Inventor
Dale Joshua Brady
Paul Frederick Scott
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Emhart Glass Machinery US Inc
Original Assignee
Emhart Industries Inc
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Filing date
Publication date
Application filed by Emhart Industries Inc filed Critical Emhart Industries Inc
Publication of EP0193403A1 publication Critical patent/EP0193403A1/de
Application granted granted Critical
Publication of EP0193403B1 publication Critical patent/EP0193403B1/de
Expired legal-status Critical Current

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/90—Investigating the presence of flaws or contamination in a container or its contents

Definitions

  • the present invention relates to inspecting glass containers and other containers having transparent or translucent sidewalls, and more particularly to inspecting such containers for forming defects such as "birdswings".
  • a variety of types of defects are known to occur in glass containers as a result of the forming process.
  • the method and apparatus of the present invention are particularly applicable to the detection of structural irregularities on the inner surface of the container sidewalls.
  • One such defect known as a "birdswing" is formed when the two sides of the container contact each other during the formation of the parison and prior to blowing the container into its final shape. At this stage the touching of the two walls of the container may cause the hot glass sides to fuse together, so that as the container is blown to its final shape the sides which have touched will move away from each other forming a small thread of glass therebetween, i.e. a "birdswing".
  • a birdswing need not comprise a complete thread between the two inner walls, inasmuch as the thin filament of glass may break rather than stretch during rapid cooling of the article. Inevitably, however, there will be a small conical protuberance from the sidewall directed toward the opposite sidewall.
  • U.S. Patent No. 4 249 075 to Lovalenti discloses an alternative apparatus for detection of birdswing defects.
  • a container under inspection is rotated and a laser is directed through the opening defined by its finish, toward the container base. If no birdswing is present, the laser beam will pass through the bottom, but the presence of a birdswing being scanned will cause the laser light to be scattered, and detected by a circumferential protocell array.
  • this detection system suffers the shortcoming that the user must accept a tradeoff between the sensitivity of this device to relatively small birdswings as against the portion of the inner container wall which will be effectively scanned.
  • U.S. Patent No. 4 165 277 to Frewin describes a monitoring unit having a plurality of scanning photodiodes with associated phototransistors. The photodiodes are sequentially energised to emit light pulses, illuminating an area of interest of the glassware. Error pulses are generated by phototransistors when a defect is sensed in light reflected from the article.
  • the Frewin apparatus designed for detection of "in the wall" defects, would not effectively descriminate between birdswings and other defects.
  • U.S. Patent No. 4 424 441 to Bieringer et al discloses photoinspection apparatus in which the container finish is illuminated with diffused light in order to monitor the finish for check-type defects having a horizontal component - an approach obviously unsuitable for detection of birdswings.
  • the apparatus of U.S. Patent No. 4 399 357 to Dorf et al. which is specially designed for detection of defects such as horizontal checks in the sidewall of a glass container, directs radiant energy into the sidewall of the container from above while the container is rotated.
  • the Dorf system trains a detector device such as a television camera on the outer sidewall to scan the container for light reflected by a horizontal check or similar defect within the sidewall.
  • the Dorf et al, apparatus would not provide sensitive and reliable detection of birdswings and similar forming defects on the interior of the container sidewalls, nor avoid undesired detection of other defects. Inasmuch as it relies on light internally transmitted through the sidewall to detect defects, it is highly vulnerable to various transmission losses.
  • a related object of the present invention is' to detect an appreciably complete percentage of birdswing defects present in the container, while avoiding signals indicative of other defects such as imperfections within the sidewall.
  • Another related object is to avoid undesired indications of embossed surface decorations on the exterior of the container sidewalls.
  • An additional object of the invention is to achieve container inspection apparatus which effectively scans the entire inner sidewall of glass containers. This object should be satisfied while providing a high sensitivity for detection of relatively small or partially formed birdswings which may appear as spikes.
  • a further object of the invention is to design apparatus for detection of birdswings which may be effectively used in tandem with inspection apparatus for other types of defects.
  • Apparatus for this purpose should be sturdy and reliable, and designed to be effectively operated by relatively unskilled users. Most desirably, these inspection devices should have an inspection capability for a variety of container types - e.g. different wall thicknesses, side wall profiles, glass colourations, etc.
  • the invention provides an apparatus for detecting inner-wall defects in transparent articles, characterised in that the apparatus comprises means for providing a partially collimated beam of light directed through a base of the article along a side wall of the article; and optical detection means placed exterior to the article to detect light emerging from the outer side wall of the article over a given scanning area.
  • An apparatus relies upon a controlled dispersion of light rays which are reflected by birdswings and similar structural imperfections at the container's inner wall, without significant reflections by "within the wall” flaws or by embossed surface decorations.
  • the illuminating column of light is confined within a limited area as it is transmitted through the base, considering a radial cross-section of the container.
  • the light beam preferably illuminates a band at the heel of the bottle which does not extend beyond the outer sidewall, and has an inner edge somewhat beyond the container's inner wall. A column of light thus confined will not cause reflections off exterior features of the container, but will illuminate the inner sidewall in a well defined manner.
  • a further aspect of the invention is the design of suitable apparatus for detecting light rays reflected by a birdswing or similar defect.
  • an array of photosensitive elements scan essentially the entire outer sidewall of the bottle. These elements produce characteristic electrical signals in response to the presence of a small region of greater than ambient luminosity.
  • the photodetector apparatus scans the entire sidewall surface by means of circumferentially disposed photosensitive devices or an equivalent optical imaging arrangement, or by rotating the container relative to a video camera or like device trained on the sidewall.
  • a variety of photodetector devices are suitable for this purpose, including, for example, video cameras or a vertical strip of point detectors.
  • Apparatus embodying the invention may be used in tandem with conventional "back lighting" photoinspection apparatus wherein the former will be sensitive to light spots, and the latter to dark spots, thereby to provide a more comprehensive glass container inspection system.
  • the invention also provides an apparatus for detecting inner-wall defects in a glassware container and the like, characterised in that the apparatus comprises an illumination source assembly, comprising a source of uncollimated light, means for projecting a portion of the uncollimated light through a base of the container along an inner sidewall of said article, and means for limiting said portion within a given area and range of incident angles at the container's base; and an optical detection assembly, for scanning light emerging from a selected area of the container sidewall, and detecting bright spots within a resulting video image.
  • an illumination source assembly comprising a source of uncollimated light, means for projecting a portion of the uncollimated light through a base of the container along an inner sidewall of said article, and means for limiting said portion within a given area and range of incident angles at the container's base
  • an optical detection assembly for scanning light emerging from a selected area of the container sidewall, and detecting bright spots within a resulting video image.
  • Inspection apparatus 10 incorporates an article conveyor 20, including an underlying conveyor 21 and flanged article holders 22, to transport glassware articles 100 past the inspection site 50.
  • a pair of resilient belts 32 and 33 nip the article finish at a rotating zone 30 to rotate the bottle as shown.
  • the relative speed of belts 32 and 33, respectively driven by pulleys 34 and 35, is chosen to provide a desired number of complete rotations, illustratively on the order of three rotations, as the article passes over the slot 49 of illumination source 40.
  • Video Out signals are received as "Video Out" signals by a monitor 68 for direct viewing, and by video processor circuitry 80.
  • Assembly 80 interprets the Video Out signals and recognises patterns indicative of -birdswings or like defects within the scanned portion of article 100.
  • Video Processor 80 receives from Position Encoder 28 indicia of the rate of advance of conveyor 20, and the phase of periodic conveyor operation, via encoded signals from Conveyor Drive 25, and coordinates this information with the Video Out Signals.
  • This optical recognition technique exploits the fact that birdswings and like features will form streaks in a multiframe video image, when scanning a rotating bottle 100.
  • the processed video signals from module 80 may be displayed on monitor 85, or upon recognition of an unacceptable forming defect may actuate Ware Reject Apparatus 90.
  • the method and apparatus of the present invention relate particularly to the "set-up", i.e. illumination technique, used for inner-wall defect detection, as more fully disclosed below.
  • Secondary aspects include the method of article transport during inspection, the photoinspection apparatus employed, and the means for interpreting the scanned video image.
  • a wide variety of alternatives may be employed for these latter elements of the inspection system.
  • article 100 could be scanned while stationary using a circumferential array of video cameras.
  • Alternative photodetector devices such as a vertical strip of photodiodes are also considered within the scope of the present invention.
  • the present apparatus is suitably integrated in a comprehensive defect inspection system, such as one that includes "back-lighting" for detecting in-the-wall defects as dark spots in the scanned image.
  • a comprehensive defect inspection system such as one that includes "back-lighting" for detecting in-the-wall defects as dark spots in the scanned image.
  • the sensitivities of the various components of such comprehensive defect systems may be individually adjusted, thus avoiding undesirable tradeoffs found in prior art multipurpose inspection systems.
  • the illumination arrangement described below provides sensitive detection of partially formed birdswings, spikes, and like inner-wall defects while avoiding spurious signals.
  • the illumination source 40 comprises various elements designed to produce an upwardly-directed beam of light through the slot 49, according to defined specifications.
  • Lamp 42 illustratively comprises an incandescent lamp which emits light over spectra within the optical passband of the transparent material of article 100.
  • the walls of cabinet 41 surrounding lamp 42 are lined with mirrors 43 of which one is seen in Figure 2, to direct uncollimated light through F resnel lens 44.
  • Light passed by Fresnel lens 44 is received by light guide assembly 45 including converging plates 46, 48, which are lined with a nonreflective material, and create a partially collimated beam of light through slot 49 (see Figure 3).
  • this light output desirably comprises a reasonably even dispersion of light rays over a range of incident angles.
  • the illustrated optics assembly 40 will provide upwardly directed light rays over a range between about 15° from vertical fanning out within bottle 100, and about 5° fanning out in an exterior direction - a dispersion which provides excellent birdswing detection characteristics as explained below. These parameters are determined by the inclination of the light guide plates 46, 48 respectively. Slot 49 is disposed near the outer edge of the heel of bottle 100 as it traverses the slot generally parallel thereto ( Figure I) .
  • Figure 4 shows somewhat schematically a partially cut-away bottle 100 illuminated for birdswing detection at the inspection site 50.
  • Light rays emerging from the light guide assembly 45 in this view represented by arrows, largely pass into the interior of bottle 100 through the glass at the heel of the bottle. It is desirable to position the slot 49 close to the outer edge of the bottle's base, but not beyond this point.
  • a suitable width for slot 49 is on the order of 1/4" - 1/2", (0.63 to 1.27 cms) depending on the diameter and wall thickness of bottle 100.
  • These light rays desirably are dispersed over a range of incident angles for reasonably accurate detection of a variety of configurations of birdswings 115.
  • this detection technique relies upon the reflection of light rays off the upper surfaces 116 of birdswings 115, to redirect these rays normally to the outer sidewall 119 of bottle 100, where they will be detected as brighter than the background level by the camera 60.
  • light directed at an angle A from vertical enters the root 114 of birdswing 115, and reflects off the upper wall 116 provided that the angle of incidence R exceeds the critical angle of 41.8 degrees for reflection at a glass-to-air boundary.
  • features such as embossed areas in the outer sidewall 119 will reflect the rays inwardly, and will not create "false positives" in the image scan data.
  • in-the-wall defects such as blisters and stones will not be recognised as inner wall defects.

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  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)
EP86301410A 1985-03-01 1986-02-27 "Vogelschwing"-Fehlererfassung für Glasbehälter Expired EP0193403B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US707267 1985-03-01
US06/707,267 US4664521A (en) 1985-03-01 1985-03-01 Birdswing defect detection for glass containers

Publications (2)

Publication Number Publication Date
EP0193403A1 true EP0193403A1 (de) 1986-09-03
EP0193403B1 EP0193403B1 (de) 1989-08-23

Family

ID=24841020

Family Applications (1)

Application Number Title Priority Date Filing Date
EP86301410A Expired EP0193403B1 (de) 1985-03-01 1986-02-27 "Vogelschwing"-Fehlererfassung für Glasbehälter

Country Status (6)

Country Link
US (1) US4664521A (de)
EP (1) EP0193403B1 (de)
JP (1) JPS61262641A (de)
AU (1) AU569696B2 (de)
CA (1) CA1254283A (de)
DE (1) DE3665222D1 (de)

Families Citing this family (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4679075A (en) * 1985-04-29 1987-07-07 Emhart Industries, Inc. Glassware inspection using optical streak detection
AU601714B2 (en) * 1987-02-18 1990-09-20 Hajime Industries Ltd. Object inspection apparatus
US5437702A (en) * 1993-08-24 1995-08-01 Coors Brewing Company Hot bottle inspection apparatus and method
US6025910A (en) * 1995-09-12 2000-02-15 Coors Brewing Company Object inspection method utilizing a corrected image to find unknown characteristic
US5734467A (en) * 1995-07-31 1998-03-31 Coors Brewing Company Inspection apparatus for high temperature environments
AU6640396A (en) * 1995-07-31 1997-02-26 Coors Brewing Company Hot bottle inspection apparatus and method
US6118526A (en) * 1996-08-16 2000-09-12 Coors Brewing Company Method for measurement of light transmittance
US6025919A (en) * 1996-08-16 2000-02-15 Coors Brewing Company Method for measurement of light transmittance
US6049379A (en) * 1997-12-30 2000-04-11 Coors Brewing Company Method for inspecting translucent objects using imaging techniques
US5935285A (en) * 1997-12-30 1999-08-10 Coors Brewing Company Method for inspecting manufactured articles
US5917602A (en) * 1998-04-30 1999-06-29 Inex Inc. System and method for image acquisition for inspection of articles on a moving conveyor
US7148961B1 (en) 2004-11-10 2006-12-12 Owens-Brockway Glass Container Inc. Container sidewall inspection
US7595870B2 (en) * 2004-11-10 2009-09-29 Owens-Brockway Glass Container Inc. Optical inspection of container walls
EP2458367B1 (de) * 2010-11-25 2015-08-05 Mettler-Toledo AG Vorrichtung und Verfahren zur Erkennung fester Substanzen in einer flüssigen Phase

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2320549A1 (fr) * 1975-08-07 1977-03-04 Ball Brothers Service Corp Procede et appareil de controle du fond de pieces de verrerie
DE2834587A1 (de) * 1977-08-11 1979-03-01 Ti Fords Ltd Flascheninspektionsvorrichtung
DE2909061A1 (de) * 1979-03-08 1980-09-11 Siemens Ag Anordnung zum pruefen von bewegten gegenstaenden mittels einer fernsehkamera
US4249075A (en) * 1978-11-20 1981-02-03 Owens-Illinois, Inc. Detection of birdswing defects in glass containers
DE3245908A1 (de) * 1982-12-11 1984-06-14 Hermann Dr.Rer.Pol. 5470 Andernach Datz Vorrichtung zum selbsttaetigen pruefen von hohlglaesern, zum beispiel flaschen mit engem hals, auf verunreinigungen durch fremdkoerper, laugen- und waschwasserreste

Family Cites Families (8)

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Publication number Priority date Publication date Assignee Title
US3629595A (en) * 1970-03-11 1971-12-21 Barry Wehmiller Co Transparent container inspection apparatus
JPS5219798B2 (de) * 1971-12-22 1977-05-30
GB1406392A (en) * 1973-03-14 1975-09-17 Barry Whemiller Co Container flaw inspection apparatus
US3932042A (en) * 1974-05-20 1976-01-13 Barry-Wehmiller Company Container inspection apparatus and method of inspection
US4063823A (en) * 1976-12-14 1977-12-20 Rame-Hart, Inc. Workpiece, and container and contents, inspecting apparatus and method
JPS5447696A (en) * 1977-09-21 1979-04-14 Nippon Keisoku Kougiyou Kk Tester for lighttpermeable body
GB2071641B (en) * 1980-02-26 1983-10-19 United Glass Ltd Apparatus for detecting defects in glass containers
US4487322A (en) * 1982-09-27 1984-12-11 Owens-Illinois, Inc. Method for inspecting glass containers

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2320549A1 (fr) * 1975-08-07 1977-03-04 Ball Brothers Service Corp Procede et appareil de controle du fond de pieces de verrerie
DE2834587A1 (de) * 1977-08-11 1979-03-01 Ti Fords Ltd Flascheninspektionsvorrichtung
US4249075A (en) * 1978-11-20 1981-02-03 Owens-Illinois, Inc. Detection of birdswing defects in glass containers
DE2909061A1 (de) * 1979-03-08 1980-09-11 Siemens Ag Anordnung zum pruefen von bewegten gegenstaenden mittels einer fernsehkamera
DE3245908A1 (de) * 1982-12-11 1984-06-14 Hermann Dr.Rer.Pol. 5470 Andernach Datz Vorrichtung zum selbsttaetigen pruefen von hohlglaesern, zum beispiel flaschen mit engem hals, auf verunreinigungen durch fremdkoerper, laugen- und waschwasserreste

Also Published As

Publication number Publication date
DE3665222D1 (en) 1989-09-28
AU5374086A (en) 1986-09-04
US4664521A (en) 1987-05-12
JPS61262641A (ja) 1986-11-20
CA1254283A (en) 1989-05-16
AU569696B2 (en) 1988-02-11
EP0193403B1 (de) 1989-08-23

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